The pope stepped out to receive a t-shirt from the group of fifth-grade students from Perugia, Italy, when he asked them who wanted to go for a ride.
From the chorus of, "Me! Me! Me!" replies, Francis picked two boys, 11-year-olds Livio Bastianelli and Davide Maria Bianchi.
"I was really excited. That never happens!," Livio told The Associated Press.
Pope Francis has made a point of connecting with people in St. Peter's Square since being elected as the leader of the Catholic Church last year.
Last Sunday, on Palm Sunday, Francis got out of his popemobile after his homily so he could take selfies with tourists from Rio de Janeiro, who had carried a large cross into the square.
In February, Pope Francis was photographed kissing his "Mini-Me" in front of a Vatican crowd. The little boy was dressed in tiny papal robes and a skull cap. The toddler's grandmother made the outfit for Carnival, when children dress up in costumes in the weeks before Lent.